Iceless freezer chest



Nov. 12, 1968 H. R. MARYLAND 3,410,109

ICELESS FREEZER CHEST Filed Jan. 9, 1967 2 Sheets-Sheet l 46 95 Fig 5 Howard R. Mary/and INVENTO i 6 102 R .44 I10 94 J Y @aofl...

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Nov. 12, 1968 H. R. MARYLAND ICELESS FREEZER CHEST 2 Sheets-Sheet 2 Filed Jan.

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United States Patent 3,410,109 ICELESS FREEZER CHEST Howard R. Maryland, P.0. Box 7, Palm Harbor, Fla. 33563 Filed Jan. 9, 1967, Ser. No. 608,078 15 Claims. (Cl. 62-457) ABSTRACT OF THE DISCLOSURE A freezer chest having a storage compartment refrigerated by vaporization of liquid nitrogen discharged under pressure into the compartment from refillable tanks housed within a separate chamber. A thermostatic valve controls the flow of nitrogen into the storage compartment in order to maintain a predetermined temperature therein while flow is cut-off whenever the storage compartment is opened.

Background of the invention This invention relates to the refrigerated storage of foodstuffs or the like and more particularly to a selfcontained freezer chest within which items are maintained in a refrigerated state without the use of any ice or externally energized refrigerating equipment.

An important object of the present invention therefore is to provide a portable, economical freezer chest within which foodstuffs or the like may be stored in a refrigerated condition for prolonged periods of time without requiring any external power.

Summary of the invention In accordance with the present invention, a freezer chest is provided having an insulated storage compartment separated by an insulated partition wall from a chamber within which at least two containers of liquefied refrigerant such as nitrogen are housed, one of which is selectively rendered operative as a source of refrigerant. The refrigerant is discharged into the storage compartment in order to produce a cooling effect because of the absorption of heat as the refrigerant is changing state and expanding volumetrically. The other container of refrigerant constitutes a standby source so that the freezer may be used for prolonged periods without refilling the tanks. Flow of refrigerant is regulated and controlled by a thermostatic valve in order to supply a quantity of refrigerant to the storage compartment sufficient only to maintain it at a desired temperature. Further, a cut-off valve is provided whereby upon opening of the closure for the storage compartment, flow of refrigerant is interrupted to avoid wasteful use of the refrigerant.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.

Brief description of thedrawings FIGURE 1 is a perspective view showing the freezer chest of the present invention with both compartments thereof opened.

FIGURE 2 is a top plan view of the freezer chest with parts broken away.

FIGURE 3 is an enlarged partial sectional view taken substantially through a plane indicated by section line 3-3 in FIGURE 2.

FIGURE 4 is a transverse sectional view taken substantially through a plane indicated by section line 44 in FIGURE 2.

FIGURE 5 is an enlarged partial sectional view of a 3,410,109 Patented Nov. 12, 1968 portion of the tank of refrigerant and outlet valve assembly.

FIGURE 6 is an enlarged partial sectional view taken substantially through a plane indicated by section line 66 in FIGURE 2.

Detailed description of the preferred embodiment Referring now to the drawings in detail, FIGURE 1 illustrates the freezer chest generally denoted by reference numeral 10 which may be in the form of a horizontally elongated housing 12 within which a storage compartment 14 is formed spaced from an operating chamber 16 by means of an insulated partition wall 18. Associated with the storage compartment, is a closure member 20 shown open in FIGURE 1 and held in the illustrated position for example by a flexible brace element 22. An access door 24 on the other hand is associated with the operating chamber 16. The closure member 20 and door 24 may be provided with latch devices 26 and 28 engageable for example with catches 30 and 32 respectively mounted on the front wall 34 and end wall 36 of the housing. It will of course be appreciated that any other suitable latch mechanism may be utilized such as magnetic latches in order to hold the closure member and door in their closed positions. Furthermore, the end walls of the housing may be provided with handles 38 to facilitate transport of the freezer chest from one location to another.

As more clearly seen in FIGURES 3 and 4, the closure member 20 includes insulation 40 and is pivotally mounted along the upper edge of the rear wall 42 by means of an elongated hinge assembly 44. The closure member is also provided with a peripheral sealing edge portion 46 which engages the upper edges of the front wall 34, the end wall 48 opposite the end wall 36 as well as the upper edge of the insulated partition wall member 18 in order to seal the storage compartment 14. The bottom wall 50 of the housing extends between the end walls 36 and 48 to form a base for foodstuffs placed within the storage compartment 14 and for equipment housed within the chamber 16. Each of the walls 34, 42, 48 and 50 are provided with an outer shell 52 forming an external surface for the housing. Insulation 54 is enclosed by an internal shell 56 for the housing walls that is corrugated within the storage compartment 14 forming vertical channels 58 on the rear wall 42, front wall 34 and end wall 48 and horizontal channels 60 on the bottom wall 50. The insulated partition wall is also formed by insulation 62 sandwiched between the vertical wall plates 64 and 66. The upper edge portion of the partition wall mounts a second hinge assembly 68 disposed perpendicular to the hinge assembly 44 so as to pivotally mount the access door 24 which is similar in construction to the closure member 20 except for dimension and disposition.

Removably mounted within the operating chamber 16 by means of a pair of clamps 70 and fastener bolts 72, are a pair of refrigerant containing tanks or containers 74 as more clearly seen in FIGURES 2 and 3. The tanks enclose a liquid refrigerant such as nitrogen under pressure and may be provided with valved inlets 76 through which the tanks may be recharged or refilled with the refrigerant. Each of the tanks as more clearly seen in FIGURE 5, includes an externally threaded neck portion 78 closed by an internally threaded cap 80 engaging an annular sealing element 82. A filling tube 82 extends into the tank and projects upwardly into the neck portion 78 mounting adjacent thereto, a one-way check valve assembly 86 of a type adapted to be opened against a spring bias by insertion of the outlet tube 88. The outlet tube extends through an opening in the cap 80 and forms a 90 bend for connection to a selectively controlled restrictor valve 90- through which the flow of liquid nitrogen from the tank 74 is controlled at a regulated rate. As shown in FIGURE 2, a selectively operated restrictor valve 90 is associated with each of the two tanks so that a regulated flow of liquid nitrogen may be conducted from one of the tanks, while the other tank is closed so that it may serve as a standby source of liquid nitrogen. Both of the selectively controlled restrictor valves 90 are therefore connected at their outlet sides to any suitable thermostatic valve 92 having a common outlet conduit 94 through which liquid nitrogen is conducted to the storage compartment. The conduit 94 extends into the partition wall 18 and is connected to a cut-off valve assembly generally referred to by reference numeral 96 mounted within the partition wall adjacent the upper edge thereof as more clearly seen in FIGURE 3. When the valve assembly 96 is opened therefore, liquid nitrogen will be conducted into the storage compartment and discharged through a nozzle assembly generally referred to by reference numeral 98.

As shown in detail in FIGURE 6, the cut-off valve assembly includes a valve body 100 interconnected between the nozzle assembly 98 and the conduit 94 to form a flow passage intersected by a valve chamber 102 within which a ball type valve element 104 is disposed. A spring 106 biases the valve element 104 against the valve seat within the valve chamber so as to block the flow passage formed in the valve body. However, the valve element is held in its open position against the bias of the spring 106 as shown in FIGURE 6 by means of a valve actuating plunger 108 that projects from the valve body upwardly through an opening in the upper edge of the partition wall assembly 18 for engagement by the closure member 20. In the closed position of the closure member as shown in FIGURE 6, the valve actuating plunger 108 in engagement therewith hold the valve element 104 in its open position against the bias of the spring 106 so that the flow of liquid nitrogen may proceed under control of the thermostatic valve 92 and at a flow rate regulated by the opened restrictor valve as aforementioned for discharge through the nozzle assembly into the storage compartment 14. However, whenever the closure member 20 is displaced to its open position as shown in FIGURE 1, the actuating plunger 108 is free to move upwardly under the bias of the spring 106 displacing the valve element 104 to its closed position. The flow of refrigerant to the storage compartment is thereby interrupted.

The outlet of the cut-off valve assembly 98 is connected by a T-coupling 110 to a transversely extending manifold 112 of the nozzle assembly as more clearly seen in FIGURES 3 and 4. The manifold thereby extends transversely across the storage compartment adjacent the upper portion thereof and is provided with a plurality of downwardly directed discharge apertures 114. A deflector shield 116 is mounted in spaced relation to the partition wall 18 enclosing the discharge manifold 112 between the partition wall and the deflector shield in order to downwardly confine the discharge flow of nitrogen. Formed on the lower half of the deflector shield, are a plurality of openings 118 from which the vaporizing nitrogen may enter the main portion of the storage compartment within which foodstuffs are to be stored. It will be apparent therefore, that as result of the heat absorbed by the nitrogen as it changes state and expands into the storage compartment, the temperature with the storage compartment is lowered. Further, since the nitrogen gas is heavier than the air, it will settle to the bottom of the storage compartment and collect within the channels 60. Further, the corrugations of the internal shell 56 of the storage compartment which form the channels 58 and 60, provide a greater surface maintained at a lowered temperature by the cooling effect of the nitrogen.

From the foregoing description, the construction, operation and utility of the freezer chest of the present invention will be apparent. It will be appreciated therefore, that a relatively economical and effective freezer chest is provided without reliance on any source of external power. Because of the regulated flow of refrigerant into the storage compartment for refrigeration thereof only when refrigeration is called for, the freezer chest will be in effective operating condition for prolonged periods of time without requiring any refilling or recharging of the tanks 74. Further, since theflow of refrigerant is cut-off each time the storage compartment is opened, there will be no wasteful use of the refrigerant. The effective operating period for the freezer chest is further prolonged because by means of the selectively controlled restrictor valves 90, the standby tank may be put into use as soon as the other tank is exhausted. In any event the arrangement described facilitates tank removal and refilling by opening the access door 24 without disturbing the items stored in the storage compartment 14.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In combination with a freezer chest having an insulated storage compartment, an operating chamber separated therefrom by an insulated partition and an insulated closure for the storage compartment, means for refrigerating the storage compartment comprising, a source of liquid refrigerant under pressure within the operating chamber, nozzle means mounted by the partition for discharging said refrigerant into the storage compartment, conduit means extending through the partition connecting the source to the nozzle means for conducting a regulated flow of refrigerant thereto, and mechanically operated valve means mounted in the partition for blocking said flow through the conduit means in response to opening of the storage compartment by said closure.

2. The combination of claim 1 wherein said source of refrigerant includes a refillable container of liquefied gas removably mounted within said chamber, a selectively opened restrictor valve connected to the container and thermostatic valve means connecting said restrictor valve to the conduit means.

3. The combination of claim 2 wherein said nozzle means comprises, an elongated manifold connected to the conduit means and extending transversely thereto, said manifold having a plurality of downwardly opening discharge apertures, and a deflector shield enclosing the manifold adjacent to the partition having a plurality of openings formed adjacent the bottom of the storage compartment.

4. The combination of claim 3 wherein said valve means includes a cut-off valve element, means biasing the valve element to a closed position, an actuating element engageable with the valve element and projecting upwardly from the partition, said closure including a sealing edge portion resting on the partition in engagement with the actuating element to hold the valve element in an open position against the bias of said biasing means.

5. The combination of claim 4 wherein said storage compartment includes an internally corrugated surface forming channels within which the refrigerant collects.

6. The combination of claim 1 wherein said nozzle means comprises, an elongated manifold connected to the conduit means and extending transversely thereto, said manifold having a plurality of downwardly opening discharge apertures, and a deflector shield enclosing the manifold adjacent to the partition having a plurality of openings formed adjacent the bottom of the storage compartment.

7. The combination of claim 6 wherein said valve means includes a cut-off valve element, means biasing the valve element to a closed position, an actuating element engageable with the valve element and projecting upward- 1y from the partition, said closure including a sealing edge portion resting on the partition in engagement with the actuating element to hold the valve element in an open position against the bias of said biasing means.

8. The combination of claim 1 wherein said valve means includes a cut-ofi valve element, means biasing the valve element to a closed position, an actuating element engageable with the valve element and projecting upwardly from the partition, said closure including a sealing edge portion resting on the partition in engagement with the actuating element to hold the valve element in an open position against the bias of said biasing means.

9. The combination of claim 1 wherein said storage compartment includes an internally corrugated surface forming channels within which the refrigerant collects.

10. The combination of claim 9 wherein said source of refrigerant includes a refillable container of liquefied gas removably mounted within said chamber, a selectively opened restrictor valv connected to the container and thermostatic valve means connecting said restrictor valve to the conduit means.

11. In combination with an insulated freezer chest having a partition forming a storage compartment on one side thereof, an insulated closure hingedly mounted on said one side of the partition for closing the storage compartment, a pair of containers removably mounted on the other side of the partition enclosing liquid refrigerant, refrigerant discharge means mounted by the partition on said one side thereof within the storage compartment, selector valve means connecting one of said containers to the discharge means for supply of refrigerant thereto and cut-off valve means engageable by the closure for conducting flow of refrigerant to the discharge means in response to closing of the storage compartment by the closure.

12. The combination of claim 11 wherein said cut-off valve means includes a valve clement, spring means biasing the valve element to a closed position blocking flow, an actuating element engageable with the valve element and projecting upwardly from the partition, said closure including a sealing edge portion resting on the partition in engagement with the actuating element to hold the valve element in an open position against the bias of said spring means.

13. The combination of claim 12 wherein said discharge means comprises, an elongated manifold connected to the conduit means and extending transversely thereto, said manifold having a plurality of downwardly opening discharge apertures, and a deflector shield enclosing the manifold adjacent to the partition having a plurality of openings formed adjacent the bottom of the storage compartment.

14. The combination of claim 11 wherein said discharge means comprises, an elongated manifold connected to the conduit means and extending transversely thereto, said manifold having a plurality of downwardly opening discharge apertures, and a deflector shield enclosing the manifold adjacent to the partition having a plurality of openings formed adjacent the bottom of the storage compartment.

15. The combination of claim 11 wherein said storage compartment includes an internally corrugated surface forming channels within which the refrigerant collects.

References Cited UNITED STATES PATENTS 966,076 8/1910 Bobrick M 62239 2,479,867 8/1949 Rosebaugh 62514 X 2,610,472 9/1952 Maxwell 62457 X 2,642,728 6/1953 Thomaras 62547 X 2,715,817 8/1955 Brodheim 62-457 X 3,109,299 11/1963 Anderson 62457 X 3,174,299 3/1965 Ellis 625 14 X 3,246,659 2/1966 Rath 62239 X 3,258,931 7/1966 Kelly et al 62514 X 3,257,820 6/1966 Case et a] 62223 LLOYD L. KING, Primary Examiner. 

